ULTIMATE STRIP STRENGTH OF PERFOBOND STRIP WITH SMALL HOLE CONFINED BY CONCRETE COVER

Abstract

The ultimate slip strength of a perfobond strip (called “PBL” hereafter) depends significantly
on the concrete confinement conditions around PBL hole as well as concrete shear fractures at the hole. If
the hole is small, the effect of concrete confinement will still more strongly appear. In this paper, focusing on
the concrete confinement due to only concrete cover by removing other confinements perfectly, the ultimate
slip strength of PBL with small hole is investigated by conducting push-out tests, in which the diameter of
the PBL hole is set at 30 mm and the thickness of concrete cover is varied from 0 to 100 mm. Test results
show that the concrete separates into two blocks with concrete crack parallel to the PBL plate and that the
ultimate slip strength of a 50-mm-thick concrete cover is 34.4 kN, which is about 10 times of the slip strength
without concrete cover (=3.5 kN). Thus, it can be concluded that thicker concrete cover makes the slip
strength remarkably larger, in the case of small-hole PBLs. In accordance with the experimental results in
this paper, a method for PBL slip strength evaluation is shown based on the concept proposed by Fujii et al.